body{
    padding-top: 50px ;
    color: #c8c8c8;
    background-color: #272b30;
}

#yongyou , #xiaoguo , #jiaocheng {
    padding: 80px;
    text-align: center;
}
#xiaoguo{
    background: #3B4045;
}
.col-md-12 , .col-md-12 {
    margin-bottom: 10px;
}
h2 {
    margin-bottom: 40px;
}
h3 {
    font-size: 18px;
}
 p{
    margin-top: 20px;
}
 #xiaoguo p{
     padding-bottom: 50px;
 }
 pre{
     border: 1px solid #000000;
     margin-bottom: 50px;
 }